In addiction, drug taking and behaviors associated with drug taking become rigid and difficult to modify. While the pharmacological actions of drugs that support addiction are well characterized, how these drugs interact with learning systems in the brain to reinforce drug taking behaviors is an open question. A better understanding of how addictive drugs co-opt natural learning and memory systems is critical for our ability to treat and prevent drug addiction. The proposed research focuses on the ability of addictive drugs to act directly on learning systems to facilitate the learning of habits, and on identifying the locations in the brain where cocaine acts to facilitate habit learning. Specific Aim #1 will test the ability of post-training injections of cocaine to facilitate habit learning in rats. By comparing behaviors paired with post-training saline injections to behaviors paired with post-training cocaine injections, the ability of cocaine to facilitate habitual responding by acting during memory consolidation will be characterized. Specific Aim #2 will then determine if areas in the brain that support the learning of natural habits are required for the ability of cocaine to facilitate habit learning. Pre-training lesions of the infralimbic cortex and the dorsolateral striatum (two critical regions for natural habit learning) will be used to test if both of these structures are required for habit facilitation by cocaine. Finally, Specific Aim #3 will test if reversible inactivation of the infralimbic cortex and dorsolateral striatum during memory consolidation can block the ability of cocaine to facilitate habit learning. PUBLIC HEALTH RELEVANCE: Drug addiction has high costs, both to affected individuals and to society as a whole. A better understanding of the mechanisms by which addictive drugs are able to influence learning and memory will provide novel targets for the treatment and prevention of drug addiction. The goals of this project are to 1) show that cocaine can act directly on habit learning systems in the brain to facilitate habit learning for behaviors that happen to occur close in time to when cocaine in administered, 2) to identify the areas of the brain which are required for the facilitation of habit learning by cocaine, and 3) to demonstrate that cocaine acts in these brain regions during memory consolidation to facilitate habit learning.